Girls want to be models, so they're ready to get on any dick that will get them a job in the modeling business. To suck or not to suck penises - such a question does not exist for them. Everyone sucks - just not everyone flaunts it. But not all of them are willing to let you work on your sweet pussy. At least the girls should be given time to get naked. There's no time to think about it. You got to ride the dick.
If your girlfriend's house is her sexy mother, always keep the bedroom door ajar. You don't want to limit your asshole to one asshole when there's another one around. Plus, she's insatiable.